Impact of social determinants on inpatient outcomes in hairy cell leukemia: A national cohort study

Abstract Background: Hairy Cell Leukemia (HCL) is a rare, indolent B-cell lymphoproliferative disorder with a generally favorable prognosis due to effective frontline therapies. However, disparities in hospitalization-related outcomes may persist due to variations in social determinants of health (SDOH). Despite their growing recognition in cancer care, the impact of SDOH on clinical outcomes in HCL remains poorly characterized, particularly in the inpatient setting. Methods: We conducted a retrospective cross-sectional analysis of adult hospitalizations with a primary or secondary diagnosis of HCL using the 2020–2022 National Inpatient Sample (NIS) databese, a nationally representative database. Key SDOH variables examined included race/ethnicity, primary payer (e.g., Medicare, Medicaid, private, self-pay), patient ZIP code–based median income quartile, hospital region, and hospital urban/rural and teaching status. Outcomes assessed were in-hospital mortality, length of stay (LOS), and total hospital costs (inflation-adjusted to 2022 USD). We applied multivariable logistic regression for mortality, negative binomial regression for LOS, and gamma regression for cost, adjusting for age and sex. All models used HC3 robust standard errors and underwent diagnostic testing to ensure model fit. Results: We identified 4,825 HCL-related hospitalizations. The cohort was with a mean age of 56.7 ± 25.2 years, 38% of the cohort was female. The overall in-hospital mortality rate was 3.7%. Increasing age was significantly associated with higher odds of in-hospital death (OR 1.04 per year; 95% CI 1.03–1.06; p<0.001). Insurance status emerged as a key predictor: self-pay patients had more than twice the odds of mortality compared to those insured by Medicare (OR 2.25; 95% CI 1.17–4.32; p=0.015), suggesting a potential role of uninsurance or underinsurance in adverse outcomes. Female patients were associated with lower resource utilization, including shorter LOS (IRR 0.81; p<0.001) and slightly reduced total costs (cost ratio 0.98; p<0.001). Hospital-related factors also influenced outcomes: urban teaching hospitals were associated with significantly longer LOS (IRR 1.34; p<0.001) and higher total costs (cost ratio 1.06; p<0.001), possibly reflecting greater clinical complexity or inefficiencies in high-volume centers. Socioeconomic context also mattered; patients from higher-income ZIP codes had modestly shorter hospital stays (IRR 0.87; p=0.023), suggesting a potential link between neighborhood level income and hospital efficiency or baseline health. Conclusions: Among patients hospitalized with HCL, both clinical and socioeconomic factors significantly influence inpatient outcomes. Age and insurance type are strong independent predictors of mortality, and it underscores the importance of health coverage in this vulnerable population. Resource utilization patterns also vary by sex, hospital characteristics, and neighborhood income, suggesting opportunities for health system-level interventions. Efforts to reduce disparities may benefit from improving access to insurance, optimizing care in urban teaching hospitals, and tailoring supportive care strategies based on patient demographics and socioeconomic context.